Coloring of bent wood products



Feb. 14, 1939. w. c. WHYTE 2,147,587

COLORING OF BENT WOOD PRODUCTS Filed May 25, 1937 INVENTOR. WILL/HM C Wy 7-5 ATTORNEY aw Feb-14,1939

COLORING OF WOOD PRODUCTS William C. Whyte, Cortland, N. Y., alslgnor toCortland Line Company, Inc, Cortland, '-aoorpmtionofNewYork IApplication my :5. 1m, Serial No. 144.000

REISSUED.

'1 Claims. (Cl. 273-73) This invention relates to improved artificiallycolored articles comprising tenacious, brilliantly dyed hardwoods andmore especially as applied to bent tennis racket frames, snow shoes,skis,

trout landing net hoops-or the like set shapes of arcuate contour. Myyed wood may be penetrated in a uniformly diffused manner to afi'ord asubstantially bright appearance throughout the .frame body and to impartan attractive, durable "L and non streaky surface finish theretothatshall not peel or scruff oil.

The harmful effects resulting from the suecessive hot dyeing, bendingandforced drying of such wood products may be minimized by consistentlyrestricting the temperature intensity and by fixing upon theallowabletotal heat treating time required to complete all operationsthereon. 'lfhe pr'esent improvements strive to so control the necessarycombined treating steps as to substantially obviate their accumulativedetrimental; heating effects upon a finished bent wood a product,particularly as regards its shock absorbing property against impactloading. In addition, my hot dyeing treatment to some extent improvesthe properties of a bent laminated racket in that augmented framerigidity and hardness are imparted thereto over its original plywoodstock. a

The same dyeing procedure admits. of fabrieating a hoop shaped framefrom a single or.

different specie of laminated wood in which the respective outer orinner plies prior'to gluing, may be dyed in'spectral hues. in acontrasting or harmonizing color scheme to heighten its decorativeappearance as a distinctive marketable commodity over the corr nding useof woods in natural colors. types of artificially colored racket framesare made to preserve adequate tensile strength and other inherentqualities by resorting to a suitable primary grade of wood that willeffectively meet I over a prolonged period of usage, the arduousrequirements (if a batlike ball striking implement without latent flawsor superficial discoloration.

The preferred grade of hardwood to be em played in the fabrication of mydyed racket fran'ie or the like, is second growth, commercial whitegash, particularly its selected straight-grained or 'ciearsapwood whichmay bemade to preserve its g any desired bright coloring matter,preferably Both, the solid and laminated,

certain kinds of water soluble, organic acid dyestuffs of an extremelysoluble character, since apparently not all of the so-called anilin orthe like synthetic dyes react in the manner herein contemplated. Thecited white sapwood of ash ranks relatively high in specific gravity,tensile strength, toughness against impact loading. bends flawlessly inrelatively thick plies, and retains its set shape to'a marked degreeafter being bent to form. 10

The fact that such wood does possess a low volumetric shrinkage from agreen state into an oven dried condition, together with its relativelysmall natural moisture content, assumes significance in restricting thetendency to swell, to 15 straighten out with increased moisture absorp-1 tion, or otherwise alter the original arcua'te shape a 'of a bentframe when subjected in use to an anticipated rather wide degree ofchange in atmospheric humidity.

A varnished, painted or shallow stained surface finish for a tennisracket frame or the like is susceptible to weather conditions and itsinherent color frailty may ultimately lead to an unsightly wornappearance. Such superficially applied coatings tend to disintegratewith age by cracking or flaking, especially as regards the swingingarched head of a tennis racket whichis likely to suffer rapid abrasioninactive service. By virtue of a uniform dye impregnation, my 30 framehead will not reveal a different underlying color, although subjected tosevere knocks or long repeated ground scraping. A shaped up product ofthis kind may also during its manufacture,

be deeply shaved oil. and sanded without change. in color.

Furthermore, tennis racket frames and the handles thereof not only callfor ample inherent strength, but should nicely be held to a definitebody size to provide for the requisite heft and 0 resulting finebalanced feel that will wholly satisfy professional playing needs.

In order to realize the maximum break down capacity in a bent laminatedracket frame, it is expedient to provide for a high degree oflongitudinal shear resistance in each component ply thereof. Inaccordance with conventional decorative practice, a soft wood inlay iscommonly inserted between stronger ash plies in their respective naturalcolors. An interposed laminago tion' of this species possesses a lowshear strength and hence is likely to correspondingly weaken a completedlaminated frame. Under break down bending tests, many of suchconventional inlays have'been found fail fromlengthwise'grain factoryperformance.

shear between the glued ply faces thereof. By resort to a dyed woodinlay possessing a markedly higher inherent shear property, it becomespossible by dyeing, to obtain a far wider color selection together withincreased strength at a materially lowered fabrication cost, thereby notonly more effectively utilizing cheaper grades of American woods such aswhite ash, but at the same time obviating the cited grain shear frailtyon part of a conventional softer inlay.

In addition, my innerand outer frame plies may without harmful results,be dyed to a color that sharply contrasts with their inlays. Woods thatpresent a sharply defined natural color, seldom afford a straight graincleavage and when attempt is made to use such weaker woods as a heavyree'nforcing outer Ply. they frequently fracture upon being closely bentto the required shape. The instant innovations pertain to the refinedfabrication of a high grade racket frame without allowing its decorativepattern to wear off under prolonged usage.

The fabricating of a tennis racket that shall prove acceptable toexperienced players by satisis a difficult art. Present day bent woodtennis frames are required to possess in high degree, appropriatequalities that can only be attained by selecting the most suitable woodspecies. Any substantial deviation from this exacting standard hasgenerally been foimd unacceptable to thetrade, it being emphasizedithata proportionate drop of less than onehalf of the maximum attainablebreak down strength of a conventional all ash racket; is

likely to result in its complete commercial relection.

The instant ballimpelling frame is preferably dyed prior to the moistbending thereof into a required hoop or other arcuate shape, whereuponthe partially treated article may be subjected to intensified or ovendrying to remove surplus'moisture at a comparatively rapid rate. Anypermanent injury resulting from such forced drying or discoloration intoa comparatively dark shade of the frame stock, may .be materiallymitigated by a careful control of the temperature elevation of the dyebath and drying over by definitely restricting the'total time duringwhich any high temperature is applied, the heat treatment in itsentirety being herein deliberately terminated prior to permitting theresidual bending strength of the treated wood to become inordinatelylowered or allowing a brilliant spectral color to become vitiated.

. The primary object of the present invention is,

to fabricate a neatly trimmed, decorative racket frame or 'the like bentshape of either solid or plywood that is dye impregnated in one or moreartificially colored base woods, the goal being to generally work forthe optimum as regards the application of a durable brilliant pattern orother pleasing color scheme to h wooden structure and thereby providesuperficial discoloration under prolonged hard usage and its result!"ing wear.

Reference is had to the accompanyi one sheet of drawings in which:

figs. 1 and? respectively represent a face and an edge view of atennis'racket treated and equipped in accordance with my invention.

Fig. 31s a cross-sectional viewof a solid racket frame as taken alongline 8-4 of;l"ig.1. I

mg.,4 is similar. to Fig. 3 but illustra es a laminated in lieu of asolid racket frame,

. heat treatment, whether amass? Figs. 5 and 6 detail a modified frameoverlay of the laminated type.

Fig. '1 fragmentally represents a laminated racket frame provided withanother style of decorative overlay.

An outstanding requirement in obtaining a socalled brilliant or brightdye shade in distinctive colors, resides in maintaining the naturalwhite or the like pale color of the sapwood (alburnum) portion of ash,or the like hardwood species against scorching without substantialdarkening by chemical changes; also in not allowing the treated woodfibers to become embrittled or brash to an extent that will seriouslyimpair the shock resisting qualities and durability thereof underfatigue loading, nor to other- -wise substantially affect the wood lifefor subsequent close bending particularly as applied to racket purposes.Incipient stages of decay induced by excessive temperature, are usuallyaccompanied by a visible discoloration and may cause heat treated woodto undergo pronounced permanent weakening under impact loading.

Such impairment is augmented in a proportionate relation to excessivetemperature exposure, wood being increasingly injured with a prolongedapplied during the dyeing or the drying steps. That is to say, theresulting loss in bending strength is accumulative and tends toprogressively darken the natural sapwood color by such scorching effectsto a point where the dyed colors of a lighter shade may be obliteratedby a darkened background and thus materially neutralize or otherwisevitiate certain color effects herein sought.

In order to secure adequate penetrationat a rapid productive rate thatwill produce a uniformly distributed, non-streaky woods,-I preferablybut not necessarily resort to a hot. dye bath held under pressure butlimit the exposure thereof to relatively high temperature for arestricted period that will notseriously impair its toughness to shocknor allow its initial pale shade to become darkened sufficiently tooverpower theparticular anilin dye or some other 4 brilliant coloringagency such as scarlet, canary, copenhagen blue, emerald green or thelike spectral hues, in which it is more particularly intended to dye mybent wood frames.

As an exemplification of a preferred procedure, the following treatmentsecures the results herein contemplated. Selected white ash sapwoodstock may initially be cut into relatively long strips having across-sectional thickness of about 95" as suitable for making anunlaminated tennis racket orsnow shoe frame of which the grain runslengthwise without abnormal diagonal slope. A large batch of suchstrips, stacked in spaced relation may then be set upright on end andimmersed in a brilliant dyeing solution held under pressure in a closedjacketed container (preferably porcelain lined and free from thepresence of iron or otherv metallic element likely to affect thedyestuff). The wood should be reasonably dry before immersion sinceexcessive moisture content tendsto resist color absorption. Said aqueousbath preferably contains a water soluble anilin dye of the characterpreviously indicated and said wooden strips may under favorableconditions, be initially heated in such solution by steam or other meansto about 250 for less than one hour's time, it being evident that thestipulated temperature may be raised or lowered .within reasonablelimits, depending upon the parcoloring in hard process without 'need offresh" steam, whereupon all the processed wooden strips becomeimpregnated to a substantially uniform shade. My initial'steam heatingsuffices to maintain the dye bath 'at an' elevated temperature withrespect to the atmosphere until the color processing is completed. Ifdesired, the usual pro-vacuum process may also be resorted to infacilitating dye impregnation, but this is not essential.

In attempting to color a batch of ash' strips in a brilliant spectralhue, the dye hot bath should not be allowed to act for "an unduly longperiod otherwise the bending strength of the dyed wood is likely tosuffer material impairment. The treated wood body first becomessuperficially penetrated by the dye and finally reaches saturation,whereupon it is preferred to terminate the dyeing operation by removingsaid strips from the closed container. Should the hot dyeing especiallyabove212 F., be unduly prolonged, the tendency is first to superficiallyscorch the, wood toward a dull brown shade, which with continuedexcessive processing creeps inwardly and finally becomes diffused overthe whole cross-sectional profile of a .dye treated wooden strip so asto dominate the desired color shade.

While in a water saturated state, such pliant and brightly colored ashstrips may individually be sharply bent without substantial fracture andretained about a suitable forming fixture to dry thereon into a loopedtennis racket frame represented in Figs. 1 to 3. In this illustrativeembodiment, a. solid frame member i after being 'dried and set, is givena closed hoop shape having the respective strip end regions extendedinto subthree bonded components including a dividingwooden center splineISA which latter may be distinctively dyed in a brilliant color shadethat contrasts with the adjoining components to constitute acharacteristic emblem by which to identify my decorative rackets to thepurchasers thereof.

Such frame structure m y be further fortified by -a glued crescentreenforcement l4 and by 7 separate fiat overlayssuch as I! or ISA buteither type of overlay may be extended into unitary formation as in Fig.-'l. Each opposed .handle side face or pallette' may ave one or morereenforcing layers or plural cheeks i6 glued thereon insuperlmposedrelation to enlarge the ban;

die girthand toenhance its decorative display. The closed hoop perimetermay be drilled in multime to thread the interwoven web strings ntherethrough.

'After the'aforesaid dyed name'stnps have respectively been bent intohoop shape, theymay be transferred into a kiln or the like agency tohasten'the drying thereof while still mounted and held around a separateforming fixture, care being taken not to overheat such bent frames so asavert honeycomb and celi collapse,

also to prevent abnormal discoloration of the treated wood or the dyeimpregnation thereof.

Bright anilin dyes when exposed to high temperature for. a prolongedperiod,,tend to go over into a darker shade and it is the present aim toobviate such color degeneration by suitably controlling my processingtime and temperatures. When too rapidly kiln or oven dried, opposed sidefaces of the treated frame strips are by abnormal core shrinkage, likelyto sink into a cupped formation which may interfere with tight gluing,especially as regards superimposed fiat plies or veneer reenforcements.

Bald kiln drying or oven baking is preferably temperature at highhumidity and then gradually changing over to a maximum temperature notin excess of 200 F. at a. relatively lowered humidity. The accelerateddrying process usually requires some 12 to 24 hours after which the setbent frames ihay be taken out of the kiln at a moisture content somewhatbelow 6 to 8%. When seasoned to atmospheric condition, the removed frameis made ready to have a throat piece and overlays applied thereto by asuitable adhesive such as animal or casein glue. v

In the event flat shoulder overlays or handle layers are provided, theymay be dyed and kiln dried in accordance with the same processprescribed for the frame strips after which they may be applied intoplace. If preferred, a group of my potential frame making strips mayinitially be dyed and bent up as a whole in boardlike formation, whichis subsequently cut into separated racket forming units.

By my refined treatment, undue darkening of the treated wood is notallowed to occur and this in turn, correspondingly prevents seriousdeterioration of the shock absorbing qualities of 'a bent racket frameor the like ball impelllng implement. When so restricted, the heattreated wood stock is not subjected to sufilclent darkening to vitallyinterfere with the application of brlllint dye of a pale shade. 'The useof air pressure in following "up the initial steaming, tends to preservethe original 'pale shade of heat treated wood stock. While the use oflower than stipulated temperatures would prolong the process somewhat,the prescribed treatment has been found to afford a commercially usefulbent wood frame that retains a high degree of its original strength.

The use of dissimilar species of more costly wood plies possessingcontrasting natural colors, is not so well adapted to fulfill exactingframe specifications in so faras their relatively lower intrinsicstrength anddiverse higher shrinkage properties are not of the samefavorable charactor as those afforded by less costly ash, nor can thesame brilliant decorative efiects be achived in natural colored woods.

As a result of extensive comparative tests, I have determinedthat ashracket frames after being dyed. bent and dryed,'may be upheld tosubstantially the same inherent strength possessed by a correspondingundyed ash frame. Plywood when processed in accordance with the hereinprescribed dyeing treatment, is further found'to enhance both thehardness and rigidity over anundyed frame of equal size. The somementedrigidity reduces frame warpage when subjected to a high initialstringing tension.

Under favorable circumstances, heart-wood or duramen may be treated by aprocess similar to 5 that described, but in such event the final colormay be expected to become somewhat darker in shade than the naturalwood. Heart-wood is inherently difficult to penetrate uniformly but suchdye distribution may be facilitated by cut- 10 ting the wood intorelatively thinner slats to more adequately surface the same. Coloredslats of this kind may be glue assembled into laminated plywood in theFig. 4 manner and then bent up into nested hoop shape.

15 In practice, after having cut ash boards into solid frame stripswholly of either sap-wood or of heart-wood, there remains a certainamount of scrap which may be utilised by further cutting the same intorelatively thin slats. Such 2o surplus material may likewise be dyetreated in the prescribed manner and worked up into iaminated racketframes i i of which adjacent nested plies may be given harmonizing orcontrasting colors. If desired, an inlay of thin basswood,

gs poplar. birch or the like in either their natural state or in anartificially colored condition, may likewisebe incorporated and gluedbetween certain of such dyed. plies. When different plies of suchlaminated wood are to be contrastingly so dyed, each color requires aseparate bath. By -.virtue of such treatment, the distinct hues of mylaminated frame present a'sharp demarcation therebetween without need ofany interposed a In a like manner, the throat overlay IIA may belaminated around the curvature axis 18 of the bent frame in the nestedfashion indicated in dotted outline in Fig. 1 and worked up intodifferent colors to correspond 'in matched registry with the pliesexposed along one frame side face. In such event, diversely coloredsegments of my unitary crescent shaped overlay may be bent up fromstraight stock and otherwise treatedinamanneressentiallysimilartotheprocess preferably dye lmp smt d in distinctive spec-- tralhues constituting a striking decorative frame him that is primarilycentered in its hoop-shape and handle neck region 20. The crotch regionof such frame may have a throat piece 21 bonded therein. The slat endportions again extend, outwardly away from such forked crotch regioninto an integral handle member I. of which the interposed neckregion ispreferably contracted wlthrespecttotbegirthofthehandlegrippobtion. Anornamental overlay such as It may be superimposed to cover a side faceportion of the throat piece and to span the respective forked 70 regionsof the bent slats IIAJIB, etc., as shown,

said overlay being laminated in upstanding edgewise registry withcorrupohding underlying slats in matched color schemeto virtuallycomplete a series of endless bands arranged concentrically 7abouttheaxisli andtherebyenhancinglyalter the embellishment afforded bythe aforesaid color trim.

By these means. it becomes possible to achieve strikingly beautifuldecorative effects and overlay modifications thereof as applied toracket purposes not heretofore attainable in natural wood colors. As anillustration, a de luxe laminated frame comprising adjoining ash pliesmay be dyed in delicate harmonizing light and dark shades of a preferredcolor such as either blue, green or red, D

and when such different tones of a single brilliant color are assembled,they provide for an exceptionally attractive racket adornment that willnot wear off. Complementary thereto, a series of handle reenforcingcheeks such as It may be similarly dyed to impart a contrasting orharmonizing color scheme thereto, the respective overlapping forwardcheek edges as at ISA then being preferably stepped and beveledtosimulate a quarter sawed effect.

-As a further variant, a fiat overlay such as 2|! may also be applied tothe side face of a racket frame. As separately detailed in Figs. 5 and6, such overlay may be laminated fiatwise and have certain pliesartificially dyed in diflerent colors 25 being completed withoutallowingthe dyed wood to become materially darkened to an extent that,will vitiate the sought for matched color shade. In the case of dyeingheart-wood to a mahogany or-the likedarker color, the anilin dye bathand length of total heating treatment must still 03 be proporlycontrolled 'for present purposes in order to counteract superficialdiscoloration by scorching and not allow the dye bath by leaching to gooff'color to a different shade while treating such wood. For instance.when dyeing a racket 4 frame to a delicate brown color tone, thesteaming temperature's hould be duly limited as to processing time toinsure a predictable color result capableof being consistently andregularly reproduced on a rapid scale to a substantially identicalshade, particularly so where the dyeing of such article is to berepeatedly held to a given delicate dark color tone. By deeplyimpregnating a racket frame as described, its surface color may bepermanently maintained without pronolmcedfadingor tendency of beingabsorbed inwardly into an imd'erlying non-colored core stratum.

- The foregoing is descriptive of a commodity that has been entirelysatisfactory in practice as so applied to the manufacture ofattractively colored frames, of bent wood, and which specificationwhenread in connection with the accompanying drawings, is believed tomake apparent to those skilled in this art, the advantages afforded bymy 66 improvements, it being understood that the more novel featuresthereof are subject to considerable latitude in execution, all withoutdeparting from the spirit and scope of my invention as definedintheappendedclaimsp VI. A laminated wooden frame assembled to includenested plies Mom and the same species of wood that are bent into acommon arcuate shapeand glued together into a unitary structure of whichcertain plies are dye impregnated in distinctive artificial colors priorto the glueing thereof and whereby ply rigidity is augmented withrespect to the similar property originally possessed by such undyedwoodspecies.

2. A unitary implement of laminated wood comprising nested plies thatare similarly bent and glued together into a given arcuate shape,certain of which plies prior to the glueing thereof are respectivelyimpregnated with a water soluble anilin dye throughout their respectivebody confines in distinctive hues.

3. A unitary impelling implement including a dye impregnated bent frameof wood stock. that is given a hoop shape having its respectiveterminals disposed in substantial parallelism "to provide for a handleand which frame by the dyeing thereof is rendered somewhat more rigidthan the original wood stock prior to the dyeing thereof, and a webstrung to span the hoop shaped portion of said frame.

4. An embellished impelling implement. having a frame of laminated woodstock including a pair of plies that are similarly bent and gluedtogether flatwise in nested relation, each such assembled ply prior tothe glueing thereof being impregnated with a different soluble syntheticdyestufi to impart distinctive artificial colors throughout therespective plies thereof and which plies by the dyeing thereof are in acomparable dried state augmented in superficial hardness with respect tothe same property originally possessed by the wood stock and renderedmore resistant to superficial abrasive wear without material injury tothe original toughness quality possessed by said stock.

5. An embellished laminated racket frame including a pair of nestedwooden slats that. are

, similarly bent and glued flatwise into a hoop shape including a forkedcrotch region from which the several slat ends extend outwardly into acommon handle having an interposed contracted neck region, correspondingexposed edge portions of said pair of slats being respectively dyeimpregnated in distinctive artificial colors to provide a decorativecolor trim for said frame, and an ornamental overlay of dyed-woodfixedly superimposed upon the aforesaid corresponding exposed slat edgesin the vicinity of said crotch region and which overlay is laminated inmatched upstanding edgewise registry along a length portion of suchunderlying slat edges, said overlay leaving a dye impregnated edgeportion of the hoop shape uncovered whereby to enhance the embellishmentafiorded by said color trim.

6. A unitary implement including a dyed-wood frame member bent into ahoop shape providing for a crotch region, an inlaid throat piece bondedinto said crotch region, and a dyed-wood overlay fixedly associated withsaid throat piece, said overlay being cross-sectionally laminatedradially around a curvature axis of the hoop shape and having thelaminations thereof directed in substantial parallelism with such axis.

'7. A unitary ball impeling frame of laminated wood comprising nestedplies that are similarly bent and glued together into hoop shape,certain of which wooden plies prior to the glueing thereof arerespectively impregnated with soluble synthetic dyestufi in distinctiveartificial colors.

wnmAMdwHY'rE.

